Optimize the display format of `gsctl desc`.

Currently the output is not beatified.
```txt
detail:
graph_id: '2'
process_id: 1595804
end_time: '2024-07-04 11:27:12'
id: '1'
log: "WARNING: Logging before InitGoogleLogging() is written to STDERR\nI0704 11:27:12.024127\
\ 1595804 loader_factory.cc:66] Registering loader: file, format:csv\nI0704 11:27:12.025439\
\ 1595804 schema.cc:1140] Parse schema version: v0.0\nI0704 11:27:12.025728 1595804\
\ schema.cc:574] prop--1 name: id type: int64 strategy: \nI0704 11:27:12.025779\
\ 1595804 schema.cc:574] prop-0 name: released type: int32 strategy: \nI0704 11:27:12.025806\
\ 1595804 schema.cc:574] prop-1 name: tagline type: string strategy: \nI0704 11:27:12.025828\
```